Hand tool for removing dents from sheet metal plates



G. 1.. STECK Aug. 25, 1959 HAND TOOL FOR REMOVING DENTS FROM SHEET METAL PLATES 2 Sheets-Sheet 1 Filed Jul 10, 1957 Jun 315.5 31516 315.7

, m m N5 mL mg C E O E G HIS ATTO/FNE Y 5, 1959 G. 1.. STECK 2,900,853

HAND TOOL FOR REMOVING DENTS FROM SHEET METAL PLATES Filed July 10, 1957 v 2 Sheets-Sheet 2 INVENTOK. GEOEGE L. 5TCK BY WM United States Patent HAND TOOL FOR REMOVING DENTS FROM SHEET IVIETAL PLATES George L. Steck, Dayton, Ohio Application July 10, 1957, Serial No. 670,914

6 Claims. (Cl. 81--15) This invention relates to a process and apparatus for metal working, and more particularly for smoothing wrinkled sheet metal surfaces, although not necessarily so limited.

The present application is a continuation-in-part of my copending application Serial No. 554,770, entitled Process and Apparatus for Metal Working and filed December 22, 1955.

This invention evolved from eiiorts to simplify the task of straightening dents and wrinkles in automobile bodies. Ordinarily, the mechanic straightens automobile body dents with a mallet and a hand-held anvil; but, in so doing, must have access to both sides of the damaged portion of the body. When the damaged body portion is a door, or a roof panel, for example, it is necessary that the interior upholstery be removed from the panel before the metal can be worked into shape. Thus, the costs of body repair are increased through the need to remove and replace interior upholstery.

Attempts have been made to design tools which can be used to straighten dents and wrinkles in a metal sheet when ready access is available to only one side of the damaged sheet. The tools designed for this purpose employ electromagnets or suction cups for gripping the metal surface so that the dent can be pulled out. For minor depressions in the metal surface these tools sometimes work successfully. However, when the metal sheet is severely deformed, such tools are ineffective and means for applying a greater force to the deformed metal surface is required.

An object of this invention is to provide a tool for engaging a sheet metal surface for the purpose of straightening dents in the surface.

Another object of this invention is to provide a process for straightening dents in sheet metal, wherein access to only one side of the sheet is required.

A further object of this invention is to provide a process for straightening dents in sheet metal, wherein the sheet metal surface is first weakened to facilitate the straightening operation, then restored to substantially its original mechanical strength.

Other objects and advantages reside in the construction of parts, the combination thereof and mode of operation, as will become more apparent from the following description.

In the drawings, Figure 1 is a perspective View of a tool for engaging sheet metal panels.

Figure 2 is a perspective view of a modification of the tool.

Figure 3 is a side elevational view of the tool of Figurel.

Figure 4 is a perspective view of an automobile door having a deformation in the surface thereof. A plurality of holes have been drilled in the deformed area.

Figure 5 is a cutaway side elevational view of the automobile door illustrating a step of the metal working process of this invention.

Figure 6 is a cut-away side elevational view of the ice automobile door illustrating another step of the process.

Figure 7 is a cutaway side elevational view of the automobile door wherein the holes drilled in the door have been plugged with solder.

Figure 8 is an enlarged view of one of the solder filled holes of Figure 7.

Figure 9 is a perspective view of an impact tool for engaging and straightening sheet metal panels.

Figure 10 is a side elevational view of the tool of Figure 9 in engagement with a metal panel shown in phantom, the figure illustrating two positions of the impact device.

Figure 11 is a longitudinal sectional view of the tool of Figure 10.

Referring to the drawings in detail, a tool 10 used in the metal working process of this invention is shown in Figures 1 and 3. The tool 10 comprises a cylindrical handle portion 12 to which is attached a shaped metal rod 14 which is of high tensile strength. The handle portion 12 illustrated is a short length of tubularmetal, steel for example; however, any shape suitable for gripping by hand and any material of suitable structural strength may be used for the handle portion. The rod 14 is joined at one end thereof to the handle portion 12 by brazing, or in any other suitable manner to insure a strong bond therebetween.

The rod 14 has been bent adjacent its other end to sub stantially a right angle so as to form an anvil portion 16. The anvil portion has an arched portion 16a intermediate the end thereof and the right angle bend in the rod 14. Intermediate the anvil portion and the handle portion, the rod 14 has been bent to form an arcuate bend 18 therein, the bend 18 providing for resilient movement of the anvil portion 16 relative to the handle portion 12.

The metal working process for which the tool 10 has been developed is illustrated in Figures 4 through 7. A dented or deformed automobile door 20 is shown in Figure 4. The dent 22 illustrated is of the type encountered when an automobile door is thrust against an upright post, the post pushing the door panel 23 inwardly substantially along the line 24.

In the first step in the repair of such a dent, a plurality of holes 26 are drilled in the dented area along the periphery of the dent 22 and along the line 24 representing the deepest penetration of the dent 22 into the door 20. The location of the holes 26 is somewhat arbitrary, the repairman being guided primarily by his past experience. In general, however, the holesshould be located where the curvature of the dented surface is greatest, the concentration of holes increasing with increasing curvature. Except where the metal panel has actually been kinked, the holes need not be placed closer together than twice the length of the anvil portion 16 of the tool 10. This distance is approximately one inch.

In the second step, a pair of tools 10 are inserted into holes 26 along the line 24 at the region of deepest penetration of the dent 22. The dent 22 is then pulled outwardly with the tools 10 by pulling on both tools at the same time. Ordinarily, the force one man can exert by pulling on the tools is insufficient to affect the dent. However, by holding both tools with one hand and strike ing the periphery of the dent with a padded mallet 28 held in the other hand, considerable force may be applied to the dented metal. In this operation, shown in Figure 5, the tools 10 are the equivalent of a hand-held anvil,

the arched portion 16a abutting the sheet metal at a point.

the perimeter of the dent 22, as shown in Figure 6. The padded mallet 28 may be, for example, an ordinary steel hammer, the head of which is covered with a protective layer of masking tape or the like.

Two tools used simultaneously have been recommended for the above step in the metal working process for the following reas'ens. First, each tool will have a teil= deney to create a localized deformity in the metal surface where the arched portion 16a of the anvil portion 16 con tacts the metal. This tendency is only half as great when two tools are used; Secondly, each impact of the mallet 28 will be transmitted to the rods 14 of each tool. By dividing the force of this impact between two tools, the chances of tool breakage are reduced.

The arcuate bend 18 is placed in each tool 10 to extend the useful life of the tool. Without this arcuate bend, the tool exhibits a pronounced tendency to break at the right angle bend adjacent the anvil portion 16 under the impact of the mallet 28. The arcuate bend, when present in the rod 14, absorbs the impact of the mallet.

The next step in the metal working process after the dented area 22 has been brought into alignment with the surface of the panel 23 involves smoothing out the surface irregularities 30 in the panel. These irregularities are worked out using a tool 10 and a mallet, engaging de'-' pressed areas with the tool and simultaneously pounding out high areaswith the mallet, as shown in Figure 6. I For detail work adjacent each hole 26, a modified tool 32 has been developed.

The tool 32, like the tool 10, comprises a handle poition 12, and a rod 14, having an arcuate bend 18 therein.

- The tools 16 and 32 differ only in the shape of the anvil portions. The tool '32 has ananvil portion 34 which is shorter than the anvil portion 16 and which arches in the direction of the handle portion 12. Thus, with the tool 32, the repairman is able to impress a localized force on the metal surface adjacent each hole 26.

After the dented area 22 has been straightened out, as illustrated in Figure 7, it remains to plug the holes 26. This is accomplished with a conventional soldering iron (not shown). The tip of a hot soldering iron is seated in the hole 26 with the body of the iron projecting nor mal to the surface of the panel 23. Flux core solder is introduced in the hole 26 to tin the walls of the hole while the iron is held in place to heat the adjacent metal. Following this, additional solder is applied liberally and allowed to flow into the hole 26. Finally, the iron is jerked from the hole. A small globule of solder 36 will remain in the hole;

The solder globule 36 adheres to the wall of the hole 26 and will also envelop a burr 38' on the back side of the panel which was created by drilling the hole 26. An enlarged sectional view of the solidified globule is shown in Figure 8; I

The final steps in repairing the panel 23 include sanding the solder globules 36,- so they are flush with the panel surface and repainting the surface.

Although the various steps in the metal working process described herein have been applied to a specific type of dent, it is not intended to thereby limit the application of this process. Clearly, with skill acquired through prac tice, a repairman can repair anydented or wrinkled sheet metal surface with this process.-

The practice of drilling holes in the sheet metal surface may, at first, appear inadvisable; in that it may be detrif mental to the strength and appearance of the repaired surface. The structural strength of the repaired surface as a whole is not materially reduced, however, since the area of metal removed by drilling is negligible compared to the totalsurface area of the dent. (Typically %4 inch holes are drilled approximately one inch apart. Thus, the material removed by drilling constitutes less than 2% of. the area of the dent.)

By concentrating the drilled holes at points where the curvature of the dented surface is greatest; the metal is weakened where bendin of the metal must be effected in order to straighten the dent. Thus, the presence of these small holes 26 facilitates the straightening process. The solder globules 38 replenish to some extent the structural strength of the weakened areas. The probability that a solder globule can be knocked out of its hole is exceedingly small. If the diameter of the hole is limited to inch or less, a pointed shaft can be driven through the globule, after sanding, without knocking the globule from the hole. 4

There are many advantages inherent in this metal working process that are not apparent from the above description. For example, there is no necessity for removing the damaged panel from the automobile or other vehicle in order to repair dents. Further, the repairman is not required to assume awkward positions in order to hammer out dents against a hand-held anvil. Whereas, some re pair techniques require two men to do the job, one man working alone can straighten dents using this process.

The repairman frequently relies on surface reflections as a guide to straightening out small surface irregularities. The paint is preferably left intact until after the dent has been straightened, for the reason that the light is better reflected from the painted surface than from an unpainted metal surface. After the dent has been renioved, the paint may then be removed, the surface polished and repainted. In many other metal working processes, this practice is limited because the repairman must observe rfleaiefis on one side of the panel and hammer oi'it depressions from the other side of the panel. The present metal working process enables full use of the surface reflection technique, since the repairman can observe the surface reflections as he works the metal. 1 Figiires 9, 10, and I1 illustrate a self-contained impact tool designed to replace the tools of Figures 1, 2, and 3 when heavy sheet metal panels,- as encountered in large buses and trucks are to be worked.

As best seen in Figure 10, this impact tool includes abutment for a cylindrical weight '62 slid ably joiirnalled upon the sleeve '50. As will be described hereinafter, this weight is utilized to deliver an impact to the rod 52.

The rod 52, formed of hardened steel of high tensile strength, projects out of one end of the sleeve 50. The outwardly projecting portion is bent to substantially a right angle to form an anvil portion 641 bevelled at 65 to facilitate penetration into a hole provided in a workpiece. The anvil portion '64 has an arched portion 64a intermediate the end thereof and the right angle semi in the rod 52. v This is analogous to the formationof the rod 16 of the tool of Figure 1. In this impact tool, however, the diameter of the rod 52 is materially greater than that employed in the tool of Figures l, 2, and 3 so as to provide a materially greater tensile strengthin the rod 52.

In the use of this impact tool, holes are bored in the sheet metal panel to be Worked in the manner described hereinbefore. Typically, these holes are inch holes accommodating a V inch rod 52. After the anvil portion of the rod 52 is inserted into one of the holes in the sheet metal panel, the weight 62 is positioned adjacent the panel as illustrated in phantom in Figure l1"; then rapidly drawn along the sleeve 50 into abiitiiient with the collar 60. The resulting impact is transferred to' the ice 52 through the sleeve 50. In this manner, a heavy metal panel, as illiistrated at 67, may be straightened The comparatively large holes formed in the sheet metal panel straightened with this impact tool are preferably filled with slugs soldered into place, however, a wide variety of inserts and compounds are available for this purpose.

By using heavy rod stock of high tensile strength for the rod 52, the need for a resiliency in the rod 52, as was required in the rod 16, is made unnecessary. The rod 52 will withstand the impact deliverable by the weight 62 with the only substantial resiliency in the system being provided by the sheet metal panel itself. Since this impact is transmitted through the threads 68 associated with the inner end of the rod 52, it is necessary to provide a considerable number of threads on this end of the rod. This distributes the impact load over a large number of threads.

It is deemed within the scope of this invention to provide yielding means in association with the rod 52 for absorbing impact delivered to the rod 52 in applica tions where such may be necessary.

Through extended impact use, the rod 52 will eventually fatigue, the rod tending to break at the right angle bend.

Breakage of this sort complicates removal of the threaded end of the rod 52. To facilitate removal of the threaded end of the rod, this end is bifurcated at 66 such that upon removal of the handle 56, the rod 52 may be unscrewed from the sleeve 59 by a suitable screw driver tool extended into the hollow of the sleeve 56.

Although the preferred embodiments of the device have been described, it will be understood that within the purview of this invention various changes may be made in the form, details, proportion and arrangement of parts, the combination thereof and mode of operation, which generally stated consist in a device capable of carrying out the objects set forth, as disclosed and defined in the appended claims.

Having thus described my invention, I claim:

1. A pull tool for use in metal working comprising a handle portion, an anvil portion, and elongate resilient rod means extending therebetwecn, said anvil portion extending substantially normal to the axis defined by said elongate resilient means and having an intermediate curved portion arching in the direction of the handle portion.

2. A pull tool for use in metal working comprising an elongate cylindrical body portion terminating at one end in a handle portion, anvil means secured to the opposite end of said body portion, said anvil means comprising a right angularly bent rod, one end of said rod threadedly engaging said body portion, the other end of said rod extending substantially normal to said body portion and having an intermediate arched portion therein projecting toward said handle portion, and means slidable upon said body portion for delivering a longitudinal impact to said body portion to subject said anvil portion to an impact.

3. A pull tool for use in metal working comprising an elongate tubular sleeve member, a handle portion threadedly engaging one end of said sleeve member, a rod threadedly engaging the opposite end of said sleeve member, said rod terminating in an anvil portion struck substantially normal to the axis defined by said sleeve member, said anvil portion having an intermediate arch therein projecting toward said handle portion, a cylindrical weight journalled for sliding axial movement on said sleeve, and means secured at the end of said sleeve opposite said anvil portion providing an abutment for said cylindrical weight, the construction and arrangement being such that upon said weight striking said abutment an impact is transmitted to said anvil portion.

4. A tool for use in metal working comprising an elongate tubular sleeve member, a handle portion detachably secured to one end of said sleeve member, an internally threaded portion adjacent the other end of said sleeve member, and rod means threadedly engaging said internally threaded portion and projecting from said sleeve member, the outwardly projecting portion of said rod means terminating in an anvil portion struck at right angles to the axis defined by said sleeve member and having an arched portion therein, the opposite end of said rod means having a bifurcated end portion, the construction and arrangement being such that, upon said handle portion being detached from said sleeve member, access is obtained to the bifurcated end portion of said rod means for removal thereof.

5. The tool according to claim 4 including a cylindrical weight journalled for sliding axial movement on said sleeve member, and means secured to said sleeve member adjacent the handle portion thereof providing an abutment for said weight.

6. A pull tool for use in metal working comprising an elongate rod of high tensile strength, a handle portion secured to one end thereof, and an anvil portion projecting at substantially a right angle to the other end thereof, the opposite ends of said rod between said handle and anvil portions being straight and in substantial linear alignment, said rod having a bent portion intermediate said opposite ends providing for resilient elongation thereof whereby said anvil portion is resiliently supported with respect to said handle portion.

References Cited in the file of this patent UNITED STATES PATENTS 481,763 Johnson Aug. 30, 1892 1,662,538 Richmond et al. Mar. 13, 1928 2,485,488 Ferguson Oct. 18, 1949 2,485,489 Ferguson Oct. 18, 1949 2,605,658 Sanchez Aug. 5, 1952 2,622,781 Polson Dec. 23, 1952 2,749,795 Boykin June 12, 1956 2,791,926 Guyton May 14, 1957 

